Lithium battery

ABSTRACT

A lithium battery includes a cathode including a cathode active material an anode including an anode active material and an organic electrolytic solution between the cathode and the anode, wherein the cathode includes a carbonaceous nanostructure, and the organic electrolytic solution includes a first lithium salt, an organic solvent, and a bicyclic sulfate-based compound represented by Formula 1 below: 
     
       
         
         
             
             
         
       
     
     wherein, in Formula 1, each of A 1 , A 2 , A 3 , and A 4  is independently a covalent bond, a substituted or unsubstituted C 1 -C 5  alkylene group, a carbonyl group, or a sulfinyl group, in which both A 1  and A 2  are not a covalent bond and both A 3  and A 4  are not a covalent bond.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 15/422,873, filed on Feb. 2, 2017, entitled “Lithium Battery”which is hereby incorporated by reference in its entirety.

Korean Patent Application No. 10-2016-0016352, filed on Feb. 12, 2016,in the Korean Intellectual Property Office, and entitled: “LithiumBattery,” is incorporated by reference herein in its entirety.

BACKGROUND 1. Field

One or more embodiments relate to lithium batteries.

2. Description of the Related Art

Lithium batteries are used as driving power sources for portableelectronic devices, including video cameras, mobile phones, notebookcomputers, and the like. Lithium secondary batteries are rechargeable athigh rates and have an energy density per unit weight that is at leastthree times as large as that of existing lead storage batteries,nickel-cadmium batteries, nickel-hydrogen batteries, or nickel-zincbatteries.

SUMMARY

Embodiments are directed to a lithium battery including a cathodeincluding a cathode active material, an anode including an anode activematerial, and an organic electrolytic solution between the cathode andthe anode. The cathode includes a carbonaceous nanostructure. Theorganic electrolytic solution includes a first lithium salt, an organicsolvent, and a bicyclic sulfate-based compound represented by Formula 1below:

wherein, in Formula 1, each of A₁, A₂, A₃, and A₄ is independently acovalent bond, a substituted or unsubstituted C₁-C₅ alkylene group, acarbonyl group, or a sulfinyl group, wherein both A₁ and A₂ are not acovalent bond and both A₃ and A₄ are not a covalent bond.

At least one of A₁, A₂, A₃, and A₄ may be an unsubstituted orsubstituted C₁-C₅ alkylene group, wherein a substituent of thesubstituted C₁-C₅ alkylene group is at least one selected from ahalogen-substituted or unsubstituted C₁-C₂₀ alkyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkenyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkynyl group, ahalogen-substituted or unsubstituted C₃-C₂₀ cycloalkenyl group, ahalogen-substituted or unsubstituted C₃-C₂₀ heterocyclic group, ahalogen-substituted or unsubstituted C₆-C₄₀ aryl group, ahalogen-substituted or unsubstituted C₂-C₄₀ heteroaryl group, or a polarfunctional group having at least one heteroatom.

At least one of A₁, A₂, A₃, and A₄ may be an unsubstituted orsubstituted C₁-C₅ alkylene group, wherein a substituent of thesubstituted C₁-C₅ alkylene group is a halogen, a methyl group, an ethylgroup, a propyl group, an isopropyl group, a butyl group, a tea-butylgroup, a trifluoromethyl group, a tetrafluoroethyl group, a phenylgroup, a naphthyl group, a tetrafluorophenyl group, a pyrrolyl group, ora pyridinyl group.

The substituted C₁-C₅ alkylene group may be substituted with a polarfunctional group including at least one heteroatom. The polar functionalgroup may be at least one selected from —F, —Cl, —Br, —I, —C(═O)OR¹⁶,—OR¹⁶, —OC(═O)OR¹⁶, —R¹⁵OC(═O)OR¹⁶, —C(═O)R¹⁶, —R¹⁵C(═O)R¹⁶, —OC(═O)R¹⁶,—R¹⁵OC(═O)R¹⁶, —C(═O)—O—C(═O)R¹⁶, —R¹⁵C(═O)—O—C(═O)R¹⁶, —SR¹⁶, —R¹⁵SR¹⁶,—SSR¹⁶, —R¹⁵SSR¹⁶, —S(═O)R¹⁶, —R¹⁵S(═O)R¹⁶, —R¹⁵C(═S)R¹⁶, —R¹⁵C(═S)SR¹⁶,—R¹⁵SO₃R¹⁶, —SO₃R¹⁶, —NNC(═S)R¹⁶, —R¹⁵NNC(═S)R¹⁶, —R¹⁵N═C═S, —NCO,—R¹⁵—NCO, —NO₂, —R¹⁵NO₂, —R¹⁵SO₂R¹⁶, —SO₂R¹⁶

In the formulae above, each of R¹¹ and R¹⁵ may be independently ahalogen-substituted or unsubstituted C₁-C₂₀ alkylene group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkenylene group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkynylene group, ahalogen-substituted or unsubstituted C₃-C₁₂ cycloalkylene group, ahalogen-substituted or unsubstituted C₆-C₄₀ arylene group, ahalogen-substituted or unsubstituted C₂-C₄₀ heteroarylene group, ahalogen-substituted or unsubstituted C₇-C₁₅ alkylarylene group, or ahalogen-substituted or unsubstituted C₇-C₁₅ aralkylene group. Each ofR¹², R¹³, R¹⁴ and R¹⁶ may be independently hydrogen, a halogen, ahalogen-substituted or unsubstituted C₁-C₂₀ alkyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkenyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkynyl group, ahalogen-substituted or unsubstituted C₃-C₁₂ cycloalkyl group, ahalogen-substituted or unsubstituted C₆-C₄₀ aryl group, ahalogen-substituted or unsubstituted C₂-C₄₀ heteroaryl group, ahalogen-substituted or unsubstituted C₇-C₁₅ alkylaryl group, ahalogen-substituted or unsubstituted C₇-C₁₅ trialkylsilyl group, or ahalogen-substituted or unsubstituted C₇-C₁₅ aralkyl group.

The bicyclic sulfate-based compound may be represented by Formula 2 or3:

wherein, in Formulae 2 and 3, each of B₁, B₂, B₃, B₄, D₁, and D₂ may beindependently —C(E₁)(E₂)-, a carbonyl group, or a sulfinyl group; andeach of E₁ and E₂ may be independently hydrogen, a halogen, ahalogen-substituted or unsubstituted C₁-C₂₀ alkyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkenyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkynyl group, ahalogen-substituted or unsubstituted C₃-C₂₀ cycloalkenyl group, ahalogen-substituted or unsubstituted C₃-C₂₀ heterocyclic group, ahalogen-substituted or unsubstituted C₆-C₄₀ aryl group, or ahalogen-substituted or unsubstituted C₂-C₄₀ heteroaryl group.

Each of E₁ and E₂ may be independently hydrogen, a halogen, ahalogen-substituted or unsubstituted C₁-C₁₀ alkyl group, ahalogen-substituted or unsubstituted C₆-C₄₀ aryl group, or ahalogen-substituted or unsubstituted C₂-C₄₀ heteroaryl group.

Each of E₁ and E₂ may be independently at least one selected fromhydrogen, fluorine (F), chlorine (Cl), bromine (Br), iodine (I), amethyl group, an ethyl group, a propyl group, an isopropyl group, abutyl group, a tert-butyl group, a trifluoromethyl group, atetrafluoroethyl group, a phenyl group, a naphthyl group, atetrafluorophenyl group, a pyrrolyl group, and a pyridinyl group.

The bicyclic sulfate-based compound may be represented by Formula 4 or5:

wherein, in Formulae 4 and 5, each of R₁, R₂, R₃, R₄, R₂₁, R₂₂, R₂₃,R₂₄, R₂₅, R₂₆, R₂₇, and R₂₈ may be independently hydrogen, a halogen, ahalogen-substituted or unsubstituted C₁-C₂₀ alkyl group, ahalogen-substituted or unsubstituted C₆-C₄₀ aryl group, or ahalogen-substituted or unsubstituted C₂-C₄₀ heteroaryl group.

Each of R₁, R₂, R₃, R₄, R₂₁, R₂₂, R₂₃, R₂₄, R₂₅, R₂₆, R₂₇, and R₂₈ maybe independently hydrogen, F, Cl, Br, I, a methyl group, an ethyl group,a propyl group, an isopropyl group, a butyl group, a tert-butyl group, atrifluoromethyl group, a tetrafluoroethyl group, a phenyl group, anaphthyl group, a tetrafluorophenyl group, a pyrrolyl group, and apyridinyl group.

The bicyclic sulfate-based compound may be represented by one ofFormulae 6 to 17 below:

An amount of the bicyclic sulfate-based compound may be from about 0.4wt % to about 4 wt % based on a total weight of the organic electrolyticsolution.

An amount of the bicyclic sulfate-based compound may be from about 0.4wt % to about 3 wt % based on a total weight of the organic electrolyticsolution.

The first lithium salt in the organic electrolytic solution may includeat least one selected from LiPF₆, LiBF₄, LiSbF₆, LiAsF₆, LiClO₄,LiCF₃SO₃, Li(CF₃SO₂)₂N, LiC₄F₉SO₃, LiAlO₂, LiAlCl₄,LiN(C_(x)F_(2x+1)SO₂)(C_(y)F_(2y+1)SO₂) where 2≤x≤20 and 2≤y≤20, LiCl,and LiI.

The organic electrolytic solution may further include a cyclic carbonatecompound, wherein the cyclic carbonate compound is selected from:vinylene carbonate (VC); VC substituted with at least one substituentselected from a halogen, a cyano (CN) group, and a nitro group (NO₂);vinylethylene carbonate (VEC); VEC substituted with at least onesubstituent selected from a halogen, CN, and NO₂; fluoroethylenecarbonate (FEC); and FEC substituted with at least one substituentselected from a halogen, CN, and NO₂.

An amount of the cyclic carbonate compound may be from about 0.01 wt %to about 5 wt % based on a total weight of the organic electrolyticsolution.

The organic electrolytic solution may further include a second lithiumsalt represented by one of Formulae 18 to 25 below:

An amount of the second lithium salt may be from about 0.1 wt % to about5 wt % based on a total weight of the organic electrolytic solution.

The carbonaceous nanostructure may include at least one selected from aone-dimensional carbonaceous nanostructure and a two-dimensionalcarbonaceous nanostructure.

The carbonaceous nanostructure may include at least one selected fromcarbon nanotubes (CNTs), carbon nanofibers, graphene, graphenenanosheets, hollow carbon, porous carbon, and mesoporous carbon.

The carbonaceous nanostructure may have an average length of about 1 μmto about 200 μm.

An amount of the carbonaceous nanostructure may be from about 0.5 wt %to about 5 wt % based on a total weight of a cathode mixture

An amount of the carbonaceous nanostructure may be from about 0.5 wt %to about 3 wt % based on a total weight of a cathode mixture.

The cathode may include a nickel-containing layered lithium transitionmetal oxide.

A content of nickel in the lithium transition metal oxide may be about60 mol % or more with respect to a total number of moles of transitionmetals.

The lithium battery may have a high voltage of about 3.8 V or higher.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of ordinary skill in the art bydescribing in detail exemplary embodiments with reference to theattached drawings in which:

FIG. 1 illustrates a graph showing discharge capacities at roomtemperature of lithium batteries manufactured according to Examples 4and 5 and Comparative Example 2;

FIG. 2 illustrates a graph showing capacity retention ratios at roomtemperature of the lithium batteries of Examples 4 and 5 and ComparativeExample 2;

FIG. 3 illustrates a graph showing discharge capacities at a hightemperature of the lithium batteries of Examples 4 and 5 and ComparativeExample 2;

FIG. 4 illustrates a graph showing capacity retention ratios at a hightemperature of the lithium batteries of Examples 4 and 5 and ComparativeExample 2;

FIG. 5 illustrates a graph showing capacity retention ratios at roomtemperature of the lithium batteries of Example 4 and ComparativeExample 2;

FIG. 6 illustrates a graph showing capacity retention ratios at a hightemperature of the lithium batteries of Example 4 and ComparativeExample 2; and

FIG. 7 illustrates a view of a lithium battery according to anembodiment.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey exemplary implementations to those skilled in the art.

A lithium battery according to an embodiment may include a cathodeincluding a cathode active material, an anode including an anode activematerial, and an organic electrolytic solution between the cathode andthe anode. The cathode may include a carbonaceous nanostructure, and theorganic electrolyte solution includes a first lithium salt, an organicsolvent, and a bicyclic sulfate-based compound represented by Formula 1below:

wherein, in Formula 1, each of A₁, A₂, A₃, and A₄ is independently acovalent bond, a substituted or unsubstituted C₁-C₅ alkylene group, acarbonyl group, or a sulfinyl group, in which both A₁ and A₂ are not acovalent bond and both A₃ and A₄ are not a covalent bond.

The organic electrolytic solution for a lithium battery, including thebicyclic sulfate-based compound as an additive, may enhance batteryperformance, such as high-temperature characteristics, lifespancharacteristics, and the like of a lithium battery.

In addition, since the cathode includes a carbonaceous nanostructure,high-temperature lifespan characteristics and high-temperature stabilityof the lithium battery may be further enhanced. In addition, theimpregnability of the cathode with respect to the electrolytic solutionmay be enhanced.

The bicyclic sulfate-based compound may have a structure in which twosulfate rings are linked to each other in a spiro form.

Without being bound to any particular theory and for betterunderstanding, a reason for which the performance of a lithium batteryis improved by addition of the bicyclic sulfate-based compound to theelectrolytic solution will now be described in further detail.

When a bicyclic sulfate-based compound is included in the electrolyticsolution, a sulfate ester group of the bicyclic sulfate-based compoundmay be reduced by itself by accepting electrons from a surface of ananode during charging, or may react with a previously-reduced polarsolvent molecule, thereby affecting characteristics of an SEI layerformed at the surface of the anode. For example, the bicyclicsulfate-based compound including the sulfate ester group may more easilyaccept electrons from an anode, as compared to polar solvents. Forexample, the bicyclic sulfate-based compound may be reduced at a lowervoltage than a polar solvent before the polar solvent is reduced.

For example, the bicyclic sulfate-based compound has a sulfate estergroup and thus may be more easily reduced and/or decomposed intoradicals and/or ions during charging. Consequently, the radicals and/orions bind with lithium ions to form an appropriate SEI layer on ananode, thereby preventing formation of a product obtained by furtherdecomposition of a solvent. The bicyclic sulfate-based compound may forma covalent bond with, for example, a carbonaceous anode itself or avariety of functional groups on the surface of the carbonaceous anode,or may be adsorbed onto the surface of an electrode. A modified SEIlayer with improved stability, formed by such binding and/or adsorption,may be more durable even after charging and discharging for a long timeperiod, as compared to an SEI layer formed from only an organic solvent.The durable modified SEI layer may in turn more effectively blockco-intercalation of the organic solvent solvating lithium ions duringintercalation of the lithium ions into an electrode. Accordingly, themodified SEI layer may more effectively block direct contact between theorganic solvent and an anode to further improve reversibility ofintercalation/deintercalation of lithium ions, resulting in an increasein discharge capacity and improvement of lifespan characteristics of thebattery fabricated.

Also, due to the inclusion of the sulfate ester group, the bicyclicsulfate-based compound may be coordinated on a surface of a cathode,thereby affecting characteristics of a protection layer formed on thesurface of the cathode. For example, the sulfate ester group may becoordinated to transition metal ions of a cathode active material toform a complex. This complex may form a modified protection layer withimproved stability that is more durable even after charging anddischarging for a long time period than a protection layer formed fromonly the organic solvent. In addition, the durable modified protectionlayer may more effectively block co-intercalation of the organic solventsolvating lithium ions during intercalation of the lithium ions into anelectrode. Accordingly, the modified protection layer may moreeffectively block direct contact between the organic solvent and thecathode to further improve the reversibility ofintercalation/deintercalation of lithium ions, resulting in increasedstability and improved lifespan characteristics of the batteryfabricated.

In addition, the bicyclic sulfate-based compound has a structure inwhich a plurality of rings are linked in a spiro form and thus has arelatively larger molecular weight than that of a general sulfate-basedcompound and accordingly, may be thermally stable.

For example, the bicyclic sulfate-based compound may form an SEI layerat a surface of an anode or a protection layer at a surface of a cathodeand may exhibit enhanced lifespan characteristics of the lithium batteryfabricated at a high temperature due to the improved thermal stability.

In the bicyclic sulfate-based compound of Formula 1 above included inthe organic electrolytic solution, at least one of A₁, A₂, A₃, and A₄may be an unsubstituted or substituted C₁-C₅ alkylene group, and asubstituent of the substituted C₁-C₅ alkylene group may be ahalogen-substituted or unsubstituted C₁-C₂₀ alkyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkenyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkynyl group, ahalogen-substituted or unsubstituted C₃-C₂₀ cycloalkenyl group, ahalogen-substituted or unsubstituted C₃-C₂₀ heterocyclic group, ahalogen-substituted or unsubstituted C₆-C₄₀ aryl group, ahalogen-substituted or unsubstituted C₂-C₄₀ heteroaryl group, or a polarfunctional group having at least one heteroatom.

For example, at least one of A₁, A₂, A₃, and A₄ may be an unsubstitutedor substituted C₁-C₅ alkylene group, and a substituent of thesubstituted C₁-C₅ alkylene group may be a halogen, a methyl group, anethyl group, a propyl group, an isopropyl group, a butyl group, atert-butyl group, a trifluoromethyl group, a tetrafluoroethyl group, aphenyl group, a naphthyl group, a tetrafluorophenyl group, a pyrrolylgroup, or a pyridinyl group. For example, the substituent of thesubstituted C₁-C₅ alkylene group may be any suitable substituentavailable for alkylene groups used in the art.

For example, in the bicyclic sulfate-based compound of Formula 1 above,the substituent of the substituted C₁-C₅ alkylene group may be a polarfunctional group having a heteroatom, and the heteroatom of the polarfunctional group may be at least one selected from oxygen, nitrogen,phosphorus, sulfur, silicon, and boron.

For example, the polar functional group having a heteroatom may be atleast one selected from —F, —Cl, —Br, —I, —C(═O)OR¹⁶, —OR¹⁶,—OC(═O)OR¹⁶, —R¹⁵OC(═O)OR¹⁶, —C(═O)R¹⁶, —R¹⁵C(═O)R¹⁶, —OC(═O)R¹⁶,—R¹⁵OC(═O)R¹⁶. —C(═O)—O—C(═O)R¹⁶, —R¹⁵C(═O)—O—C(═O)R¹⁶, —SR¹⁶, —R¹⁵SR¹⁶,—SSR¹⁶, —R¹⁵SSR¹⁶, —S(═O)R¹⁶. —R¹⁵S(═O)R¹⁶, —R¹⁵)C(═S)R¹⁶,—R¹⁵C(═S)SR¹⁶, —R¹⁵SO₃R¹⁶, —SO₃R¹⁶, —NNC(═S)R¹⁶, —R¹⁵NNC(═S)R¹⁶,—R¹⁵N═C═S, —NCO, —R¹⁵—NCO, —NO₂, —R¹⁵NO₂, —R¹⁵SO₂R¹⁶, —SO₂R¹⁶,

In the above formulae, each of R¹¹ and R¹⁵ may be independently ahalogen-substituted or unsubstituted C₁-C₂₀ alkylene group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkenylene group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkynylene group, ahalogen-substituted or unsubstituted C₃-C₁₂ cycloalkylene group, ahalogen-substituted or unsubstituted C₆-C₄₀ arylene group, ahalogen-substituted or unsubstituted C₂-C₄₀ heteroarylene group, ahalogen-substituted or unsubstituted C₇-C₁₅ alkylarylene group, or ahalogen-substituted or unsubstituted C₇-C₁₅ aralkylene group; and eachof R¹², R¹³, R¹⁴ and R¹⁶ may be independently hydrogen, a halogen, ahalogen-substituted or unsubstituted C₁-C₂₀ alkyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkenyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkynyl group, ahalogen-substituted or unsubstituted C₃-C₁₂ cycloalkyl group, ahalogen-substituted or unsubstituted C₆-C₄₀ aryl group, ahalogen-substituted or unsubstituted C₂-C₄₀ heteroaryl group, ahalogen-substituted or unsubstituted C₇-C₁₅ alkylaryl group, ahalogen-substituted or unsubstituted C₇-C₁₅ trialkylsilyl group, or ahalogen-substituted or unsubstituted C₇-C₁₅ aralkyl group.

For example, in the polar functional group having a heteroatom, ahalogen substituent of the alkyl group, the alkenyl group, the alkynylgroup, the cycloalkyl group, the aryl group, the heteroaryl group, thealkylaryl group, the trialkylsilyl group, or the aralkyl group may befluorine (F).

For example, the bicyclic sulfate-based compound included in the organicelectrolytic solution may be represented by Formula 2 or 3:

wherein, in Formulae 2 and 3, each of B₁, B₂, B₃, B₄, D₁, and D₂ may beindependently —C(E₁)(E₂)-, a carbonyl group, or a sulfinyl group; andeach of E₁ and E₂ may be independently hydrogen, a halogen, ahalogen-substituted or unsubstituted C₁-C₂₀ alkyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkenyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkynyl group, ahalogen-substituted or unsubstituted C₃-C₂₀ cycloalkenyl group, ahalogen-substituted or unsubstituted C₃-C₂₀ heterocyclic group, ahalogen-substituted or unsubstituted C₆-C₄₀ aryl group, or ahalogen-substituted or unsubstituted C₂-C₄₀ heteroaryl group.

For example, each of E₁ and E₂ may be independently hydrogen, a halogen,a halogen-substituted or unsubstituted C₁-C₁₀ alkyl group, ahalogen-substituted or unsubstituted C₆-C₄₀ aryl group, or ahalogen-substituted or unsubstituted C₂-C₄₀ heteroaryl group.

For example, each of E₁ and E₂ may be independently hydrogen, F,chlorine (Cl), bromine (Br), iodine (I), a methyl group, an ethyl group,a propyl group, an isopropyl group, a butyl group, a tert-butyl group, atrifluoromethyl group, a tetrafluoroethyl group, a phenyl group, anaphthyl group, a tetrafluorophenyl group, a pyrrolyl group, or apyridinyl group.

For example, each of E₁ and E₂ may be independently hydrogen, F, amethyl group, an ethyl group, a trifluoromethyl group, atetrafluoroethyl group, or a phenyl group.

For example, the bicyclic sulfate-based compound may be represented byFormula 4 or 5:

wherein, in Formulae 4 and 5, each of R₁, R₂, R₃, R₄, R₂₁, R₂₂, R₂₃,R₂₄, R₂₅, R₂₆, R₂₇, and R₂₈ may be independently hydrogen, a halogen, ahalogen-substituted or unsubstituted C₁-C₂₀ alkyl group, ahalogen-substituted or unsubstituted C₆-C₄₀ aryl group, or ahalogen-substituted or unsubstituted C₂-C₄₀ heteroaryl group.

For example, in Formulae 4 and 5 above, each of R₁, R₂, R₃, R₄, R₂₁,R₂₂, R₂₃, R₂₄, R₂₅, R₂₆, R₂₇, and R₂₈ may be independently hydrogen, F,Cl, Br, I, a methyl group, an ethyl group, a propyl group, an isopropylgroup, a butyl group, a tert-butyl group, a trifluoromethyl group, atetrafluoroethyl group, a phenyl group, a naphthyl group, atetrafluorophenyl group, a pyrrole group, or a pyridine group.

For example, in Formulae 4 and 5 above, each of R₁, R₂, R₃, R₄, R₂₁,R₂₂, R₂₃, R₂₄, R₂₅, R₂₆, R₂₇, and R₂₈ may be independently hydrogen, F,a methyl group, an ethyl group, a propyl group, a trifluoromethyl group,a tetrafluoroethyl group, or a phenyl group.

In particular, the bicyclic sulfate-based compound may be represented byone of Formulae 6 to 17:

As used herein, a and b of the expression “C_(a)-C_(b)” indicates thenumber of carbon atoms of a particular functional group. For example,the functional group may include a to b carbon atoms. For example, theexpression “C₁-C₄ alkyl group” means an alkyl group having 1 to 4 carbonatoms, i.e., CH₃—, CH₃CH₂—, CH₃CH₂CH₂—, (CH₃)₂CH—, CH₃CH₂CH₂CH₂—,CH₃CH₂CH(CH₃)— and (CH₃)₃C—.

A particular radical may be called a mono-radical or a di-radicaldepending on the context. For example, when a substituent needs twobinding sites for binding with the rest of the molecule, the substituentmay be understood as a di-radical. For example, a substituent specifiedas an alkyl group that needs two binding sites may be a di-radical, suchas —CH₂—, —CH₂CH₂—, —CH₂CH(CH₃)CH₂—, or the like. The term “alkylene” asused herein clearly indicates that the radical is a di-radical.

The terms “alkyl group” and “alkylene group” as used herein refer to abranched or unbranched aliphatic hydrocarbon group. In an embodiment,the alkyl group may be substituted or unsubstituted. Examples of thealkyl group include a methyl group, an ethyl group, a propyl group, anisopropyl group, a butyl group, an isobutyl group, a tert-butyl group, apentyl group, a hexyl group, a cyclopropyl group, a cyclopentyl group, acyclohexyl group, and a cycloheptyl group, each of which may beoptionally substituted or unsubstituted. In an embodiment, the alkylgroup may have 1 to 6 carbon atoms. For example, a C₁-C₆ alkyl group maybe methyl, ethyl, propyl, isopropyl, butyl, iso-butyl, sec-butyl,pentyl, 3-pentyl, hexyl, or the like.

The term “cycloalkyl group” as used herein means a fully saturatedcarbocyclic ring or ring system. For example, the cycloalkyl group maybe cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

The term “alkenyl group” as used herein refers to a hydrocarbon grouphaving 2 to 20 carbon atoms with at least one carbon-carbon double bond.Examples of the alkenyl group include an ethenyl group, a 1-propenylgroup, a 2-propenyl group, a 2-methyl-1-propenyl group, a 1-butenylgroup, a 2-butenyl group, a cyclopropenyl group, a cyclopentenyl group,a cyclohexenyl group, and a cycloheptenyl group. In an embodiment, thesealkenyl groups may be substituted or unsubstituted. In an embodiment,the alkenyl group may have 2 to 40 carbon atoms.

The term “alkynyl group” as used herein refers to a hydrocarbon grouphaving 2 to 20 carbon atoms with at least one carbon-carbon triple bond.Examples of the alkynyl group include an ethynyl group, a 1-propynylgroup, a 1-butynyl group, and a 2-butynyl group. In an embodiment, thesealkynyl groups may be substituted or unsubstituted. In an embodiment,the alkynyl group may have 2 to 40 carbon atoms.

The term “aromatic” as used herein refers to a ring or ring system witha conjugated π electron system, and may refer to a carbocyclic aromaticgroup (e.g., a phenyl group) and a heterocyclic aromatic group (e.g.,pyridine). In this regard, an aromatic ring system as a whole mayinclude a monocyclic ring or a fused polycyclic ring (i.e., a ring thatshares adjacent atom pairs).

The term “aryl group” as used herein refers to an aromatic ring or ringsystem (i.e., a ring fused from at least two rings that shares twoadjacent carbon atoms) having only carbon atoms in its backbone. Whenthe aryl group is a ring system, each ring in the ring system isaromatic. Examples of the aryl group include a phenyl group, a biphenylgroup, a naphthyl group, a phenanthrenyl group, and naphthacenyl group.These aryl groups may be substituted or unsubstituted.

The term “heteroaryl group” as used herein refers to an aromatic ringsystem with one ring or plural fused rings, in which at least one ringatom is not carbon, i.e., a heteroatom. In the fused ring system, atleast one heteroatom may be present in only one ring. For example, theheteroatom may be oxygen, sulfur, or nitrogen. Examples of theheteroaryl group include a furanyl group, a thienyl group, an imidazolylgroup, a quinazolinyl group, a quinolinyl group, an isoquinolinyl group,a quinoxalinyl group, a pyridinyl group, a pyrrolyl group, an oxazolylgroup, and an indolyl group.

The terms “aralkyl group” and “alkylaryl group” as used herein refer toan aryl group linked as a substituent via an alkylene group, such as aC₇-C₁₄ aralkyl group. Examples of the aralkyl group or alkylaryl groupinclude a benzyl group, a 2-phenylethyl group, a 3-phenylpropyl group,and a naphthylalkyl group. In an embodiment, the alkylene group may be alower alkylene group (i.e., a C₁-C₄ alkylene group).

The term “cycloalkenyl group” as used herein refers to a non-aromaticcarbocyclic ring or ring system with at least one double bond. Forexample, the cycloalkenyl group may be a cyclohexenyl group.

The term “heterocyclic group” as used herein refers to a non-aromaticring or ring system having at least one heteroatom in its ring backbone.

The term “halogen” as used herein refers to a stable element belongingto Group 17 of the periodic table, for example, fluorine, chlorine,bromine, or iodine. For example, the halogen may be fluorine and/orchlorine.

In the present specification, a substituent may be derived bysubstitution of at least one hydrogen atom in an unsubstituted mothergroup with another atom or a functional group. Unless stated otherwise,the term “substituted” means that the above-listed functional groups aresubstituted with at least one substituent selected from a C₁-C₄₀ alkylgroup, a C₂-C₄₀ alkenyl group, a C₃-C₄₀ cycloalkyl group, a C₃-C₄₀cycloalkenyl group, and a C₇-C₄₀ aryl group. The phrase “optionallysubstituted” as used herein means that the functional groups describedabove may be substituted with the aforementioned substituents.

The amount of the bicyclic sulfate-based compound of Formula 1 as anadditive in the organic electrolytic solution may range from about 0.4wt % to about 5 wt % based on the total weight of the organicelectrolytic solution. For example, the amount of the bicyclicsulfate-based compound of Formula 1 in the organic electrolytic solutionmay range from about 0.4 wt % to about 3 wt % based on the total weightof the organic electrolytic solution. For example, the amount of thebicyclic sulfate-based compound of Formula 1 in the organic electrolyticsolution may range from about 0.5 wt % to about 3 wt % based on thetotal weight of the organic electrolytic solution. For example, theamount of the bicyclic sulfate-based compound of Formula 1 in theorganic electrolytic solution may range from about 0.6 wt % to about 3wt % based on the total weight of the organic electrolytic solution. Forexample, the amount of the bicyclic sulfate-based compound of Formula 1in the organic electrolytic solution may range from about 0.7 wt % toabout 3 wt % based on the total weight of the organic electrolyticsolution. For example, the amount of the bicyclic sulfate-based compoundof Formula 1 in the organic electrolytic solution may range from about0.4 wt % to about 2.5 wt % based on the total weight of the organicelectrolytic solution. For example, the amount of the bicyclicsulfate-based compound of Formula 1 in the organic electrolytic solutionmay range from about 0.4 wt % to about 2 wt % based on the total weightof the organic electrolytic solution. For example, the amount of thebicyclic sulfate-based compound of Formula 1 in the organic electrolyticsolution may range from about 0.4 wt % to about 1.5 wt % based on thetotal weight of the organic electrolytic solution. When the amount ofthe bicyclic sulfate-based compound of Formula 1 is within the rangesdescribed above, further enhanced battery characteristics may beobtained.

The first lithium salt included in the organic electrolytic solution mayinclude at least one selected from LiPF₆, LiBF₄, LiSbF₆, LiAsF₆, LiClO₄,LiCF₃SO₃, Li(CF₃SO₂)₂N, LiC₄F₉SO₃, LiAlO₂, LiAlCl₄,LiN(C_(x)F_(2x+1)SO₂)(C_(y)F_(2y+1)SO₂) where 2≤x≤20 and 2≤y≤20, LiCl,and LiI.

The concentration of the first lithium salt in the organic electrolyticsolution may be, for example, from about 0.01 M to about 2.0 M. Theconcentration of the first lithium salt in the organic electrolyticsolution may be appropriately adjusted as desired. When theconcentration of the first lithium salt is within the above range, abattery with further enhanced characteristics may be obtained.

The organic solvent included in the organic electrolytic solution may bea low-boiling point solvent. The low-boiling point solvent refers to asolvent having a boiling point of 200° C. or less at 1 atmosphere at 25°C.

For example, the organic solvent may include at least one selected froma dialkyl carbonate, a cyclic carbonate, a linear or cyclic ester, alinear or cyclic amide, an alicyclic nitrile, a linear or cyclic ether,and derivatives thereof.

For example, the organic solvent may include at least one selected fromdimethyl carbonate (DMC), ethyl methyl carbonate (EMC), methyl propylcarbonate, ethyl propyl carbonate, diethyl carbonate (DEC), dipropylcarbonate, propylene carbonate (PC), ethylene carbonate (EC), butylenecarbonate, ethyl propionate, ethyl butyrate, acetonitrile,succinonitrile (SN), dimethyl sulfoxide, dimethylformamide,dimethylacetamide, γ-valerolactone, γ-butyrolactone, andtetrahydrofuran. For example, the organic solvent may be any suitablesolvent having a low-boiling point available in the art.

The organic electrolytic solution may further include other additives inaddition to the bicyclic sulfate-based compound. Due to the furtherinclusion of other additives, a lithium battery with further enhancedperformance may be obtained.

The additives further included in the organic electrolytic solution mayinclude a cyclic carbonate compound, a second lithium salt, and thelike.

For example, the organic electrolytic solution may further include acyclic carbonate compound as an additive. The cyclic carbonate compoundused as an additive may be selected from: vinylene carbonate (VC); VCsubstituted with at least one substituent selected from a halogen, acyano (CN) group, and a nitro group (NO₂); vinyl ethylene carbonate(VEC); VEC substituted with at least one substituent selected from ahalogen. CN, and NO₂; fluoroethylene carbonate (FEC); and FECsubstituted with at least one substituent selected from a halogen, CN,and NO₂. When the organic electrolytic solution further includes acyclic carbonate compound as an additive, a lithium battery includingthe organic electrolytic solution may have further enhanced charge anddischarge characteristics.

The amount of the cyclic carbonate compound in the organic electrolyticsolution may be, for example, from about 0.01 wt % to about 5 wt % basedon the total weight of the organic electrolytic solution. The amount ofthe cyclic carbonate compound may be appropriately adjusted as desired.For example, the amount of the cyclic carbonate compound in the organicelectrolytic solution may be from about 0.1 wt % to about 5 wt % basedon the total weight of the organic electrolytic solution. For example,the amount of the cyclic carbonate compound in the organic electrolyticsolution may be from about 0.1 wt % to about 4 wt % based on the totalweight of the organic electrolytic solution. For example, the amount ofthe cyclic carbonate compound in the organic electrolytic solution maybe from about 0.1 wt % to about 3 wt % based on the total weight of theorganic electrolytic solution. For example, the amount of the cycliccarbonate compound in the organic electrolytic solution may be fromabout 0.1 wt % to about 2 wt % based on the total weight of the organicelectrolytic solution. For example, the amount of the cyclic carbonatecompound in the organic electrolytic solution may be from about 0.2 wt %to about 2 wt % based on the total weight of the organic electrolyticsolution. For example, the amount of the cyclic carbonate compound inthe organic electrolytic solution may be from about 0.2 wt % to about1.5 wt % based on the total weight of the organic electrolytic solution.When the amount of the cyclic carbonate compound is within the aboveranges, a battery with further enhanced characteristics may be obtained.

For example, the organic electrolytic solution may further include asecond lithium salt as an additive. The second lithium salt isdistinguished from the first lithium salt, and an anion thereof may beoxalate, PO₂F₂—, N(SO₂F)₂—, or the like. For example, the second lithiumsalt may be a compound represented by one of Formulae 18 to 25 below:

The amount of the second lithium salt in the organic electrolyticsolution may be, for example, from about 0.1 wt % to about 5 wt % basedon the total weight of the organic electrolytic solution. The amount ofthe second lithium salt may be appropriately adjusted as desired. Forexample, the amount of the second lithium salt in the organicelectrolytic solution may be from about 0.1 wt % to about 4.5 wt % basedon the total weight of the organic electrolytic solution. For example,the amount of the second lithium salt in the organic electrolyticsolution may be from about 0.1 wt % to about 4 wt % based on the totalweight of the organic electrolytic solution. For example, the amount ofthe second lithium salt in the organic electrolytic solution may be fromabout 0.1 wt % to about 3 wt % based on the total weight of the organicelectrolytic solution. For example, the amount of the second lithiumsalt in the organic electrolytic solution may be from about 0.1 wt % toabout 2 wt % based on the total weight of the organic electrolyticsolution. For example, the amount of the second lithium salt in theorganic electrolytic solution may be from about 0.2 wt % to about 2 wt %based on the total weight of the organic electrolytic solution. Forexample, the amount of the second lithium salt in the organicelectrolytic solution may be from about 0.2 wt % to about 1.5 wt % basedon the total weight of the organic electrolytic solution. When theamount of the second lithium salt is within the above ranges, a batterywith further enhanced characteristics may be obtained.

The organic electrolytic solution may be in a liquid or gel state. Theorganic electrolytic solution may be prepared by adding the firstlithium salt and the additive described above to the aforementionedorganic solvent.

The carbonaceous nanostructure included in the cathode of the lithiumbattery may be at least one selected from a one-dimensional carbonaceousnanostructure and a two-dimensional carbonaceous nanostructure. Forexample, the carbonaceous nanostructure may be carbon nanotubes (CNTs),carbon nanofibers, graphene, graphene nanosheets, hollow carbon, porouscarbon, mesoporous carbon, or the like.

The carbonaceous nanostructure may have a length of about 1 μm to about180, 1 μm to about 200 μm, about 2 μm to about 160 μm, about 3 μm toabout 140 μm, about 4 μm to about 120 μm, or about 5 μm to about 100 μm.When the length of the carbonaceous nanostructure is within the aboveranges, lifespan characteristics and high-temperature stability of thelithium battery may be further enhanced. The term “length of thecarbonaceous nanostructure” as used herein refers to a maximum value ofa distance between opposite ends of a plurality of carbonaceousnanostructures. In the present specification, the term “average length”of the carbonaceous nanostructures refers to a calculated average of thelengths of the plurality of carbonaceous nanostructures.

The amount of the carbonaceous nanostructure included in the cathode ofthe lithium battery may range from about 0.5 wt % to about 5 wt %, about0.5 wt % to about 3 wt %, about 0.5 wt % to about 2.5 wt %, about 0.5 wt% to about 2 wt %, or about 0.5 wt % to about 1.5 wt %, based on a totalweight of a cathode mixture. When the amount of the carbonaceousnanostructure is within the above ranges, the impregnability of thecathode with respect to the electrolytic solution may be furtherenhanced. Due to the enhanced impregnability, the electrolytic solutionis uniformly distributed in the cathode, and thus a side reactionbetween the cathode and the electrolytic solution is suppressed.Accordingly, the lithium battery including the electrolytic solutionwith enhanced impregnability has a reduced internal resistance, and as aresult, cycle characteristics of the lithium battery are enhanced. Inaddition, the time taken for the assembly of a lithium battery isshortened due to the enhanced impregnability, and thus productivity isincreased in a lithium battery manufacturing process.

Examples of types of the lithium battery include lithium secondarybatteries such as a lithium ion battery, a lithium ion polymer battery,a lithium sulfur battery, and the like, and lithium primary batteries.

For example, in the lithium battery, the anode may include graphite. Forexample, in the lithium battery, the cathode may include anickel-containing layered lithium transition metal oxide. For example,the lithium battery may have a high voltage of about 3.80 V or higher.For example, the lithium battery may have a high voltage of about 4.0 Vor higher. For example, the lithium battery may have a high voltage ofabout 4.35 V or higher.

The nickel-containing layered lithium transition metal oxide included inthe cathode of the lithium battery is represented by, for example,Formula 26 below:

Li_(a)Ni_(x)Co_(y)M_(z)O_(2-b)A_(b)  <Formula 26>

wherein, in Formula 26, 1.0≤a≤1.2, 0≤b≤0.2, 0.6≤x<1, 0<y≤0.2, 0<z≤0.2,and x+y+z=1; M is at least one selected from manganese (Mn), vanadium(V), magnesium (Mg), gallium (Ga), silicon (Si), tungsten (W),molybdenum (Mo), iron (Fe), chromium (Cr), copper (Cu), zinc (Zn),titanium (Ti), aluminum (Al), and boron (B); and A is fluorine (F),sulfur (S), chlorine (Cl), bromine (Br), or a combination thereof. Forexample, 0.7≤x<1, 0<y≤0.15, 0<z≤0.15, and x+y+z=1. For example,0.75≤x<1, 0<y≤0.125, 0<z≤0.125, and x+y+z=1. For example, 0.8≤x<1,0<y≤0.1, 0<z≤0.1, and x+y+z=1. For example, 0.85≤x<1, 0<y≤0.075,0<z≤0.075, and x+y+z=1.

The nickel-containing layered lithium transition metal oxide included inthe cathode of the lithium battery is represented by, for example,Formula 27 or 28:

LiNi_(x)Co_(y)Mn_(z)O₂  <Formula 27>

LiNi_(x)Co_(y)Al_(z)O₂  <Formula 28>

wherein, in Formulae 27 and 28, 0.6≤x≤0.95, 0<y≤0.2, 0<z≤0.2, andx+y+z=1. For example, 0.7≤x≤0.95, 0<y≤0.15, 0<z≤0.15, and x+y+z=1. Forexample, 0.75≤x≤0.95, 0<y≤0.125, 0<z≤0.125, and x+y+z=1. For example,0.8≤x≤0.95, 0<y≤0.1, 0<z≤0.1, and x+y+z=1. For example, 0.85≤x≤0.95,0<y≤0.075, 0<z≤0.075, and x+y+z=1.

For example, the lithium battery may be manufactured using the followingmethod.

A cathode may be prepared by a suitable method. For example, a cathodeactive material composition, in which a cathode active material, aconductive material, a binder, and a solvent are mixed, is prepared. Thecathode active material composition may be directly coated onto a metalcurrent collector, thereby completing the manufacture of a cathodeplate. In another embodiment, the cathode active material compositionmay be cast onto a separate support and a film separated from thesupport may be laminated onto a metal current collector, therebycompleting the manufacture of a cathode plate.

The cathode active material may be a suitable lithium-containing metaloxide used in the art. For example, the cathode active material may be acompound represented by any one of Formulae: Li_(a)A_(1-b)B′_(b)D₂ where0.90≤a≤1.8 and 0≤b≤0.5; Li_(a)E_(1-b)B′_(b)O_(2-c)D_(c) where0.90≤a≤1.8, 0≤b≤0.5, and 0≤c≤0.05; LiE_(2-b)B′_(b)O_(4-c)D_(c) where0≤b≤0.5 and 0≤c≤0.05; Li_(a)Ni_(1-b-c)Co_(b)B′_(c)D_(α) where0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, and 0<α≤2;Li_(a)Ni_(1-b-c)Co_(b)B′_(c)O_(2-α)F′_(α) where 0.90≤a≤1.8, 0≤b≤0.5,0≤c≤0.05, and 0<α<2; Li_(a)Ni_(1-b-c)Co_(b)B′_(c)O_(2-α)F′₂ where0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, and 0<α<2;Li_(a)Ni_(1-b-c)Mn_(b)B′_(c)D_(α) where 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05,and 0<α<2; Li_(a)Ni_(1-b-c)Mn_(b)B′_(c)O_(2-α)F′_(α) where 0.90≤a≤1.8,0≤b≤0.5, 0≤c≤0.05, and 0<α<2; Li_(a)Ni_(1-b-c)Mn_(b)B′_(c)O_(2-α)F′₂where 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, and 0<α<2; Li_(a)Ni_(b)E_(c)G_(d)O₂where 0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, and 0.001≤d≤0.1;Li_(a)Ni_(b)Co_(c)Mn_(d)GeO₂ where 0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5,0≤d≤0.5, and 0.001≤e≤0.1; Li_(a)NiG_(b)O₂ where 0.90≤a≤1.8 and0.001≤b≤0.1; Li_(a)CoG_(b)O₂ wherein 0.90≤a≤1.8 and 0.001≤b≤0.1;Li_(a)MnG_(b)O₂ where 0.90≤a≤1.8 and 0.001≤b≤0.1; Li_(a)Mn₂G_(b)O₄ where0.90≤a≤1.8 and 0.001≤b≤0.1; QO₂; QS₂; LiQS₂; V₂O₅; LiV₂O₅; LiI′O₂;LiNiVO₄; Li_((3-f))J₂(PO₄)₃ where 0≤f≤2; Li_((3-f))Fe₂(PO₄)₃ where0≤f≤2; and LiFePO₄.

In the formulae above, A may be selected from nickel (Ni), cobalt (Co),manganese (Mn), and combinations thereof; B′ may be selected fromaluminum (Al), Ni, Co, manganese (Mn), chromium (Cr), iron (Fe),magnesium (Mg), strontium (Sr), vanadium (V), a rare earth element, andcombinations thereof; D may be selected from oxygen (O), fluorine (F),sulfur (S), phosphorus (P), and combinations thereof; E may be selectedfrom Co, Mn, and combinations thereof; F′ may be selected from F, S, P,and combinations thereof; G may be selected from Al, Cr, Mn, Fe, Mg,lanthanum (La), cerium (Ce), Sr, V, and combinations thereof; Q may beselected from titanium (Ti), molybdenum (Mo), Mn, and combinationsthereof; I′ may be selected from Cr, V, Fe, scandium (Sc), yttrium (Y),and combinations thereof; and J may be selected from V, Cr, Mn, Co, Ni,copper (Cu), and combinations thereof.

For example, the cathode active material may be LiCoO₂, LiMn_(x)O_(2x)where x=1 or 2, LiNi_(1-x)Mn_(x)O_(2x) where 0<x<1,LiNi_(1-x-y)Co_(x)Mn_(y)O₂ where 0≤x≤0.5 and 0≤y≤0.5, LiFePO₄, or thelike.

In addition, the lithium-containing metal oxides described above used asa cathode active material may have a coating layer at their surfaces. Inanother embodiment, a mixture of a lithium-containing metal oxide and alithium-containing metal oxide with a coating layer at a surface thereofmay be used. The coating layer may include a coating element compound,such as an oxide of a coating element, a hydroxide of a coating element,an oxyhydroxide of a coating element, an oxycarbonate of a coatingelement, or a hydroxycarbonate of a coating element. The coating elementcompounds may be amorphous or crystalline. The coating element includedin the coating layer may be selected from Mg, Al, Co, potassium (K),sodium (Na), calcium (Ca), silicon (Si), Ti, V, tin (Sn), germanium(Ge), gallium (Ga), boron (B), arsenic (As), zirconium (Zr), andmixtures thereof. A coating layer may be formed by using the coatingelements in the aforementioned compounds by using any one of variousmethods that do not adversely affect physical properties of the cathodeactive material (e.g., spray coating, dipping, or the like). The coatinglayer formation methods may be obvious to one of ordinary skill in theart and thus a detailed description thereof will not be provided herein.

A suitable conductive material may be used. The conductive material maybe, for example, carbon black, graphite particulates, or the like.

The binder may be a suitable binder used in the art. Examples of thebinder include a vinylidene fluoride/hexafluoropropylene copolymer,polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethylmethacrylate, polytetrafluoroethylene, mixtures thereof, and a styrenebutadiene rubber-based polymer.

The solvent may be, for example, N-methylpyrrolidone, acetone, water, orthe like.

The amounts of the cathode active material, the conductive material, thebinder, and the solvent may be the same level as those used in a generallithium battery. At least one of the conductive material, the binder,and the solvent may not be used according to the use and constitution ofdesired lithium batteries.

An anode may be prepared by a suitable fabrication method. For example,an anode active material composition is prepared by mixing an anodeactive material, a conductive material, a binder, and a solvent. Theanode active material composition may be directly coated onto a metalcurrent collector and dried to obtain an anode plate. In someimplementations, the anode active material composition may be cast ontoa separate support and a film separated from the support may belaminated onto a metal current collector to complete the fabrication ofan anode plate.

As the anode active material, any anode active material of lithiumbatteries used in the art may be used. For example, the anode activematerial may include at least one selected from lithium metal, a metalalloyable with lithium, a transition metal oxide, a non-transition metaloxide, and a carbonaceous material.

For example, the metal alloyable with lithium may be Si, Sn, Al, Ge,lead (Pb), bismuth (Bi), antimony (Sb), a Si—Y′ alloy (Y′ is an alkalimetal, an alkali earth metal, Group 13 and 14 elements, a transitionmetal, a rare earth element, or a combination thereof, and is not Si), aSn—Y′ alloy (Y′ is an alkali metal, an alkali earth metal, Group 13 and14 elements, a transition metal, a rare earth element, or a combinationthereof, and is not Sn), or the like. The element Y′ may be selectedfrom Mg, Ca, Sr, barium (Ba), radium (Ra), Sc, Y, Ti, Zr, hafnium (Hf),rutherfordium (Rf), V, niobium (Nb), tantalum (Ta), dubnium (Db), Cr,Mo, tungsten (W), seaborgium (Sg), technetium (Tc), rhenium (Re),bohrium (Bh), Fe, Pb, ruthenium (Ru), osmium (Os), hassium (Hs), rhodium(Rh), iridium (Ir), palladium (Pd), platinum (Pt), Cu, silver (Ag), gold(Au), zinc (Zn), cadmium (Cd), B, Al, Ga, Sn, indium (In), Ge, P. As,Sb, Bi, S, selenium (Se), tellurium (Te), polonium (Po), andcombinations thereof.

For example, the transition metal oxide may be lithium titanium oxide,vanadium oxide, lithium vanadium oxide, or the like.

For example, the non-transition metal oxide may be SnO₂, SiO_(x) where0<x<2, or the like.

For example, the carbonaceous material may be crystalline carbon,amorphous carbon, or a mixture thereof. Examples of the crystallinecarbon include natural graphite and artificial graphite, each of whichhas an irregular form or is in the form of a plate, a flake, a sphere,or a fiber. Examples of the amorphous carbon include soft carbon(low-temperature calcined carbon), hard carbon, mesophase pitchcarbonized product, and calcined coke.

In the anode active material composition, a conductive material and abinder that are the same as those used in the cathode active materialcomposition may be used.

The amounts of the anode active material, the conductive material, thebinder, and the solvent may be the same level as those used in a generallithium battery. At least one of the conductive material, the binder,and the solvent may not be used according to the use and constitution ofdesired lithium batteries.

A suitable separator to be disposed between the cathode and the anodemay be prepared. As the separator, a separator having low resistance totransfer of ions in an electrolyte and high electrolyte-retainingability may be used. Examples of the separator may include glass fiber,polyester, Teflon, polyethylene, polypropylene, polytetrafluoroethylene(PTFE), and combinations thereof, each of which may be a non-woven orwoven fabric. For example, a windable separator formed of polyethylene,polypropylene, or the like may be used in lithium ion batteries, and aseparator having a high organic electrolytic solution-retaining abilitymay be used in lithium ion polymer batteries. For example, the separatormay be manufactured according to the following method.

A polymer resin, a filler, and a solvent may be mixed together toprepare a separator composition. Then, the separator composition may bedirectly coated on an electrode and dried to form a separator. Inanother embodiment, the separator composition may be cast on a supportand dried, and then a separator film separated from the support may belaminated on an upper portion of an electrode, thereby completing themanufacture of a separator.

Suitable materials used in binders of electrode plates may in themanufacture of the separator. For example, the polymer resin may be avinylidene fluoride/hexafluoropropylene copolymer, PVDF,polyacrylonitrile, polymethyl methacrylate, a mixture thereof, or thelike.

The organic electrolytic solution described above may be prepared.

As illustrated in FIG. 7, a lithium battery 1 includes a cathode 3, ananode 2, and a separator 4. The cathode 3, the anode 2, and theseparator 4 are wound or folded and then accommodated in a battery case5. Subsequently, the organic electrolytic solution is injected into thebattery case 5, and the battery case 5 is sealed with a cap assembly 6,thereby completing the manufacture of the lithium battery 1. The batterycase 5 may have a cylindrical, rectangular or thin film shape.

The separator 4 may be disposed between the cathode 3 and the anode 2 toform a battery assembly. A plurality of battery assemblies may bestacked in a bi-cell structure and impregnated with the organicelectrolytic solution, and the resultant is put into a pouch andhermetically sealed, thereby completing the manufacture of a lithiumbattery.

The battery assemblies may be stacked to form a battery pack. Such abattery pack may be used in devices requiring high capacity andhigh-power output. For example, the battery pack may be used in notebookcomputers, smart phones, electric vehicles, and the like.

The lithium battery may have excellent lifespan characteristics and highrate characteristics and thus may be used in electric vehicles (EVs).For example, the lithium battery may be used in hybrid vehicles such asa plug-in hybrid electric vehicle (PHEV) or the like. The lithiumbattery may also be used in fields requiring the storage of a largeamount of power. For example, the lithium battery may be used inelectric bikes, motor-driven tools, or the like.

The following Examples and Comparative Examples are provided in order tohighlight characteristics of one or more embodiments, but it will beunderstood that the Examples and Comparative Examples are not to beconstrued as limiting the scope of the embodiments, nor are theComparative Examples to be construed as being outside the scope of theembodiments. Further, it will be understood that the embodiments are notlimited to the particular details described in the Examples andComparative Examples.

Synthesis of Additive

Preparation Example 1: Synthesis of Compound of Formula 3

The compound of Formula 3 may be prepared according to Reaction Scheme 1below:

Synthesis of Compound A

68.0 g (0.499 mol) of pentaerythritol and 100 g of molecular sieve (Type4A) were added to a mixed solvent of tetrahydrofuran (THF) anddichloromethane (DCM, CH₂Cl₂) in a volume ratio of 1:1 and the resultingsolution was refluxed for 20 minutes. Subsequently, 110 ml (2.8 equiv.,1.40 mol) of thionyl chloride (SOCl₂) was added to the resultant and theresultant solution was refluxed for 8 hours until the pentaerythritolwas completely consumed by reaction, to obtain a light yellow solution.The obtained light yellow solution was filtered and concentrated toobtain a residue including a light yellow solid. Thereafter, 1 L of asaturated sodium hydrogen carbonate (NaHCO₃) solution was directly addedto the residue at a rate at which effervescence was minimized, to obtaina suspension. The suspension was vigorously stirred for 20 minutes.Thereafter, the suspension was filtered and the obtained solid was addedto 1 L of purified water to prepare a mixture. Then, the mixture wasvigorously stirred for 20 minutes, subjected to suction filtration, anddried in air to obtain 104.61 g (0.458 mol) of Compound A (yield: 92%).

¹H-NMR and ¹³C-NMR data of Compound A were same as those in documents.

Synthesis of Compound B

As shown in Reaction Scheme 1 above, Compound B represented by Formula 6below was synthesized from Compound A according to a method disclosed inCanadian Journal of Chemistry, 79, 2001, page 1042.

The synthesized compound was recrystallized in a mixed solvent of1,2-dichloroethane and acetonitrile in a volume ratio of 2:1, which wasthen used in the preparation of an electrolytic solution.

Preparation of Organic Electrolytic Solution

Example 1: SEI-1316 1.0 wt %

0.90 M LiPF₆ as a lithium salt and 1 wt % of the compound of Formula 6were added to a mixed solvent of ethylene carbonate (EC), ethyl methylcarbonate (EMC), and diethyl carbonate (DEC) in a volume ratio of 3:5:2to prepare an organic electrolytic solution.

Example 2: SEI-1316 1.0 wt %+VC 0.5 wt %

An organic electrolytic solution was prepared in the same manner as inExample 1, except that 1 wt % of the compound of Formula 6 and 0.5 wt %of vinylene carbonate (VC) were used as additives.

Example 3: SEI-1316 0.5 wt %

An organic electrolytic solution was prepared in the same manner as inExample 1, except that the amount of the compound of Formula 6 used asan additive was changed to 0.5 wt %.

Example 8: SEI-1316 2 wt %

An organic electrolytic solution was prepared in the same manner as inExample 1, except that the amount of the compound of Formula 6 as anadditive was changed to 2 wt %.

Example 9: SEI-1316 3 wt %

An organic electrolytic solution was prepared in the same manner as inExample 1, except that the amount of the compound of Formula 6 as anadditive was changed to 3 wt %.

Example 9a: SEI-1316 4 wt %

An organic electrolytic solution was prepared in the same manner as inExample 1, except that the amount of the compound of Formula 6 as anadditive was changed to 4 wt %.

Example 10: SEI-1316 5 wt %

An organic electrolytic solution was prepared in the same manner as inExample 1, except that the amount of the compound of Formula 6 as anadditive was changed to 5 wt %.

Comparative Example 1: SEI-1316 0 wt %

An organic electrolytic solution was prepared in the same manner as inExample 1, except that the compound of Formula 6 as an additive was notused.

Manufacture of Lithium Battery (Examples 1-1 to 3-1 and ComparativeExample 1-1) Example 1-1

Manufacture of Anode

98 wt % of artificial graphite (BSG-L manufactured by Tianjin BTR NewEnergy Technology Co., Ltd.), 1.0 wt % of styrene-butadiene rubber (SBR)(manufactured by Zeon) as a binder, and 1.0 wt % of carboxymethylcellulose (CMC) (manufactured by NIPPON A&L) were mixed together, themixture was added to distilled water, and the resulting solution wasstirred using a mechanical stirrer for 60 minutes to prepare an anodeactive material slurry. The anode active material slurry was applied,using a doctor blade, onto a copper (Cu) current collector having athickness of 10 μm to a thickness of about 60 μm, and the currentcollector was dried in a hot-air dryer at 100° C. for 0.5 hours,followed by further drying under conditions: in vacuum at 120° C. for 4hours, and roll-pressed, thereby completing the manufacture of an anodeplate.

Manufacture of Cathode

97.45 wt % of LiNi_(1/3)Co_(1/3)Mn_(1/3)O₂, 0.5 wt % of powder-typeartificial graphite (SFG6 manufactured by Timcal) as a conductivematerial, 0.7 wt % of carbon black (Ketjen black manufactured by ECP),0.25 wt % of modified acrylonitrile rubber (BM-720H manufactured by ZeonCorporation), 0.9 wt % of polyvinylidene fluoride (PVdF, S6020manufactured by Solvay), and 0.2 wt % of PVdF (S5130 manufactured bySolvay) were mixed together, the mixture was added toN-methyl-2-pyrrolidone as a solvent, and the resulting solution wasstirred using a mechanical stirrer for 30 minutes to prepare a cathodeactive material slurry. The cathode active material slurry was applied,using a doctor blade, onto an aluminum (Al) current collector having athickness of 20 μm to a thickness of about 60 and the current collectorwas dried in a hot-air dryer at 100° C. for 0.5 hours, followed byfurther drying under conditions: in vacuum at 120° C. for 4 hours, androll-pressed, thereby completing the manufacture of a cathode plate.

A polyethylene separator having a thickness of 14 μm, a cathode side ofwhich was coated with ceramic, and the organic electrolytic solutionprepared according to Example 1 were used to complete the manufacture ofa lithium battery.

Examples 2-1 and 3-1

Lithium batteries were manufactured in the same manner as in Example1-1, except that the organic electrolytic solutions prepared accordingto Examples 2 and 3, respectively were used instead of the organicelectrolytic solution of Example 1.

Comparative Example 1-1

A lithium battery was manufactured in the same manner as in Example 4,except that the organic electrolytic solution prepared according toComparative Example 1 was used instead of the organic electrolyticsolution of Example 1.

Evaluation Example 1: Evaluation of Charge and Discharge Characteristicsat 4.25 V and Room Temperature (25° C.)

The lithium batteries manufactured according to Examples 1-1 to 3-1 andComparative Example 1-1 were each charged at a constant current of 0.1 Crate at 25° C. until the voltage reached 4.25 V (vs. Li) and then, whilemaintaining a constant voltage of 4.25 V, the charging process was cutoff at a current of 0.05 C rate. Subsequently, each lithium battery wasdischarged with a constant current of 0.1 C rate until the voltagereached 2.8 V (vs. Li) (formation operation, 1^(st) cycle).

Each lithium battery after the 1^(st) cycle of the formation operationwas charged at a constant current of 0.2 C rate at 25° C. until thevoltage reached 4.25 V (vs. Li) and then, while maintaining a constantvoltage of 4.25 V, the charging process was cut off at a current of 0.05C rate. Subsequently, each lithium battery was discharged at a constantcurrent of 0.2 C rate until the voltage reached 2.8 V (vs. Li)(formation operation, 2^(nd) cycle).

Each lithium battery after the 2^(nd) cycle of the formation operationwas charged at a constant current of 1.0 C rate at 25° C. until thevoltage reached 4.25 V (vs. Li) and then, while maintaining a constantvoltage of 4.25 V, the charging process was cut off at a current of 0.05C rate. Subsequently, each lithium battery was discharged at a constantcurrent of 1.0 C rate until the voltage reached 2.75 V (vs. Li), andthis cycle of charging and discharging was repeated 380 times.

In all the cycles of charging and discharging, there was a rest periodof 10 minutes at the end of each cycle of charging/discharging.

A part of the charging and discharging experiment results is shown inTable 1 below and FIGS. 1 and 2. A capacity retention ratio at the380^(th) cycle is defined using Equation 1 below:

Capacity retention ratio=[discharge capacity at 380^(th) cycle/dischargecapacity at 1^(st) cycle]×100  Equation 1

TABLE 1 Discharge capacity at Capacity retention ratio at 380^(th) cycle[mAh/g] 380^(th) cycle [%] Example 1-1 202 75 Example 2-1 228 82Comparative 173 63 Example 1-1

As shown in Table 1 and FIGS. 1 and 2, the lithium batteries of Examples1-1 and 2-1 including the additives according to embodiments of thepresent disclosure exhibited, at room temperature, significantlyenhanced discharge capacities and lifespan characteristics, as comparedto the lithium battery of Comparative Example 1-1 not including such anadditive.

Evaluation Example 2: Evaluation of Charge and Discharge Characteristicsat 4.25 V and High Temperature (45° C.)

Charge and discharge characteristics of the lithium batteries ofExamples 1-1 to 3-1 and Comparative Example 1-1 were evaluated using thesame method as that used in Evaluation Example 1, except that thecharging and discharging temperature was changed to 45° C. Meanwhile,the number of charging and discharging cycles was changed to 200 cycles.

A part of the charging and discharging experiment results is shown inTable 2 below and FIGS. 3 and 4. A capacity retention ratio at the200^(th) cycle is defined using Equation 2 below:

Capacity retention ratio=[discharge capacity at 200^(th) cycle/dischargecapacity at 1^(st) cycle]×100  Equation 2

TABLE 2 Discharge capacity at Capacity retention ratio at 200^(th) cycle[mAh/g] 200^(th) cycle [%] Example 1-1 249 83 Example 2-1 255 84Comparative 235 79 Example 1-1

As shown in Table 2 and FIGS. 3 and 4, the lithium batteries of Examples1-1 and 2-1 including the additives according to embodiments of thepresent disclosure exhibited, at a high temperature, significantlyenhanced discharge capacities and lifespan characteristics, as comparedto the lithium battery of Comparative Example 1-1 not including such anadditive.

Evaluation Example 3: Evaluation of Charge and Discharge Characteristicsat 4.30 V and Room Temperature (25° C.)

The lithium batteries of Example 1-1 and Comparative Example 1-1 wereeach charged at a constant current of 0.1 C rate at 25° C. until thevoltage reached 4.30 V (vs. Li) and then, while maintaining a constantvoltage of 4.30 V, the charging process was cut off at a current of 0.05C rate. Subsequently, each lithium battery was discharged at a constantcurrent of 0.1 C rate until the voltage reached 2.8 V (vs. Li)(formation operation, 1^(st) cycle).

Each lithium battery after the 1^(st) cycle of the formation operationwas charged at a constant current of 0.2 C rate at 25° C. until thevoltage reached 4.30 V (vs. Li) and then, while maintaining a constantvoltage of 4.30 V, the charging process was cut off at a current of 0.05C rate. Subsequently, each lithium battery was discharged at a constantcurrent of 0.2 C rate until the voltage reached 2.8 V (vs. Li)(formation operation, 2^(nd) cycle).

Each lithium battery after the 2^(nd) cycle of the formation operationwas charged at a constant current of 0.5 C rate at 25° C. until thevoltage reached 4.30 V (vs. Li) and then, while maintaining a constantvoltage of 4.30 V, the charging process was cut off at a current of 0.05C rate. Subsequently, each lithium battery was discharged at a constantcurrent of 1.0 C rate until the voltage reached 2.75 V (vs. Li), andthis cycle of charging and discharging was repeated 250 times.

In all the cycles of charging and discharging, there was a rest periodof 10 minutes at the end of each cycle of charging/discharging.

A part of the charging and discharging experiment results is shown inTable 3 below and FIG. 5. A capacity retention ratio at 250^(th) cycleis defined using Equation 3 below:

Capacity retention ratio=[discharge capacity at 250^(th) cycle/dischargecapacity at 1^(st) cycle]×100  Equation 3

TABLE 3 Discharge capacity at Capacity retention ratio at 250^(th) cycle[mAh/g] 250^(th) cycle [%] Example 1-1 171 84 Comparative 154 77 Example1-1

As shown in Table 3 and FIG. 5, the lithium battery of Example 1-1including the additive according to an embodiment of the presentdisclosure exhibited, at room temperature, significantly enhanceddischarge capacity and lifespan characteristics, as compared to thelithium battery of Comparative Example 1-1 not including such anadditive.

Evaluation Example 4: Evaluation of Charge and Discharge Characteristicsat 4.30 V and High Temperature (45° C.)

Charge and discharge characteristics of the lithium batteries of Example1-1 and Comparative Example 1-1 were evaluated using the same method asthat used in Evaluation Example 3, except that the charging anddischarging temperature was changed to 45° C. Also, the number ofcharging and discharging cycles was changed to 200 cycles.

A part of the charging and discharging experiment results is shown inTable 4 below and FIG. 6. A capacity retention ratio at the 200^(th)cycle is defined using Equation 4 below:

Capacity retention ratio=[discharge capacity at 200^(th) cycle/dischargecapacity at 1^(st) cycle]×100  Equation 4

TABLE 4 Discharge capacity at Capacity retention ratio at 200^(th) cycle[mAh/g] 200^(th) cycle [%] Example 1-1 189 90 Comparative 174 84 Example1-1

As shown in Table 4 and FIG. 6, the lithium battery of Example 1-1including the additive according to an embodiment of the presentdisclosure exhibited, at a high temperature, significantly enhanceddischarge capacity and lifespan characteristics, as compared to thelithium battery of Comparative Example 1-1 not including such anadditive.

Evaluation Example 5: High-Temperature (60° C.) Stability Evaluation

The lithium batteries of Examples 1-1 to 3-1 and Comparative Example 1-1were subjected to the 1^(st) cycle of charging and discharging asfollows. Each lithium battery was charged at a constant current of 0.5 Crate at 25° C. until the voltage reached 4.3 V and then, whilemaintaining a constant voltage of 4.3 V, each lithium battery wascharged until the current reached 0.05 C and then discharged at aconstant current of 0.5 C rate until the voltage reached 2.8 V.

Each lithium battery was subjected to the 2^(nd) cycle of charging anddischarging as follows. Each lithium battery was charged at a constantcurrent of 0.5 C rate until the voltage reached 4.3 V and then, whilemaintaining a constant voltage of 4.3 V, each lithium battery wascharged until the current reached 0.05 C and then discharged at aconstant current of 0.2 C rate until the voltage reached 2.8 V.

Each lithium battery was subjected to the 3^(rd) cycle of charging anddischarging as follows. Each lithium battery was charged at a constantcurrent of 0.5 C rate until the voltage reached 4.3 V and then, whilemaintaining a constant voltage of 4.3 V, each lithium battery wascharged until the current reached 0.05 C and then discharged at aconstant current of 0.2 C rate until the voltage reached 2.80 V. Adischarge capacity at the 3^(rd) cycle was regarded as a standardcapacity.

Each lithium battery was subjected to the 4^(th) cycle of charging anddischarging as follows. Each lithium battery was charged at 0.5 C rateuntil the voltage reached 4.30 V and then, while maintaining a constantvoltage of 4.30 V, each lithium battery was charged until the currentreached 0.05 C, the charged battery was stored in an oven at 60° C. for10 days and 30 days, and then the battery was taken out of the oven andthen discharged at 0.1 C rate until the voltage reached 2.80 V.

A part of the charging and discharging evaluation results is shown inTable 5 below. A capacity retention ratio after the high-temperaturestorage is defined using Equation 5 below:

Capacity retention ratio after high-temperature storage [%]=[dischargecapacity at high temperature at 4^(th) cycle/standardcapacity]×100(herein, the standard capacity is a discharge capacity at3^(rd) cycle)  Equation 5

TABLE 5 Capacity retention ratio Capacity retention ratio after 10-daystorage [%] after 30-day storage [%] Example 3-1 91 87 Comparative 90 86Example 1-1

As shown in Table 5, the lithium battery of Example 3-1 including theorganic electrolytic solution according to an embodiment of the presentdisclosure exhibited significantly enhanced high-temperature stability,as compared to the lithium battery of Comparative Example 1-1 notincluding the organic electrolytic solution of the present invention.

Evaluation Example 6: Direct Current Internal Resistance (DC-IR)Evaluation after High-Temperature (60° C.) Storage

DC-IR of each of the lithium batteries of Examples 1-1 to 3-1 andComparative Example 1-1, before being left sit in a 60° C. oven, after10-day storage in an oven at 60° C., and after 30-day storage in an ovenat 60° C., was measured at room temperature (25° C.) using the followingmethod.

Each lithium battery was subjected to 1^(st) cycle of charging anddischarging as follows. Each lithium battery was charged at a current of0.5 C until the voltage reached 50% SOC (state of charge), the chargingprocess was cut off at 0.02 C, and then each lithium battery rested for10 minutes. Subsequently, each lithium battery was subjected to thefollowing processes: discharging at a constant current of 0.5 C for 30seconds, followed by resting for 30 seconds, and charging at a constantcurrent of 0.5 C for 30 seconds, followed by resting for 10 minutes;discharging at a constant current of 1.0 C for 30 minutes, followed byresting for 30 seconds, and charging at a constant current of 0.5 C for1 minute, followed by resting for 10 minutes; discharging at a constantcurrent of 2.0 C for 30 seconds, followed by resting for 30 seconds, andcharging at a constant current of 0.5 C for 2 minutes, followed byresting for 10 minutes; discharging at a constant current of 3.0 C for30 seconds, followed by resting for 30 seconds, and charging at aconstant current of 0.5 C for 2 minutes, followed by resting for 10minutes.

An average voltage drop value for 30 seconds at each C-rate is a directcurrent voltage value.

A part of DC-IR increases calculated from measured initial DC-IRs andthe measured DC-IRs after high-temperature storage is shown in Table 6below. A DC-IR increase is represented by Equation 6 below:

Direct current internal resistance increase [%]=[direct current internalresistance after high-temperature storage/initial direct currentinternal resistance]×100  Equation 6

TABLE 6 DC-IR increase after DC-IR increase after 10-day storage [%]30-day storage [%] Example 3-1 113 125 Comparative 122 137 Example 1-1

As shown in Table 6, the lithium battery of Example 3-1 including theorganic electrolytic solution according to an embodiment of the presentdisclosure exhibited a decrease in DC-IR increase after high-temperaturestorage, as compared to the lithium battery of Comparative Example 1-1not including the organic electrolytic solution.

Manufacture of Lithium Battery (Examples G1 to G9, Reference Examples G1to G4 and Comparative Examples G1 and G2) Example G1: CNT 50 μm 0.5 wt%+SEI-1316 1 wt %

Manufacture of Anode

98 wt % of artificial graphite (BSG-L manufactured by Tianjin BTR NewEnergy Technology Co., Ltd.), 1.0 wt % of SBR (manufactured by ZEON) asa binder, and 1.0 wt % of CMC (manufactured by NIPPON A&L) were mixedtogether, the mixture was added to distilled water, and the resultingsolution was stirred using a mechanical stirrer for 60 minutes toprepare an anode active material slurry. The anode active materialslurry was applied, using a doctor blade, onto a Cu current collectorhaving a thickness of 10 μm to a thickness of about 60 μm, and thecurrent collector was dried in a hot-air dryer at 100° C. for 0.5 hours,followed by further drying in vacuum at 120° C. for 4 hours, androll-pressed, thereby completing the manufacture of an anode plate.

Manufacture of Cathode

96.95 wt % of Li_(1.02)Ni_(0.60)Co_(0.20)Mn_(0.20)O₂, 0.5 wt % of carbonnanotubes (CNTs) having an average length of 50 μm, 0.5 wt % ofpowder-type artificial graphite (SFG6 manufactured by Timcal) as aconductive material, 0.7 wt % of carbon black (Ketjen black manufacturedby ECP), 0.25 wt % of modified acrylonitrile rubber (BM-720Hmanufactured by Leon Corporation), 0.9 wt % of PVdF (S6020 manufacturedby Solvay), and 0.2 wt % of PVdF (S5130 manufactured by Solvay) weremixed together, the mixture was added to N-methyl-2-pyrrolidone as asolvent, and the resulting solution was stirred using a mechanicalstirrer for 30 minutes to prepare a cathode active material slurry. Thecathode active material slurry was applied, using a doctor blade, ontoan Al current collector having a thickness of 20 μm to a thickness ofabout 60 μm, and the current collector was dried in a hot-air dryer at100° C. for 0.5 hours, followed by further drying in vacuum at 120° C.for 4 hours, and roll-pressed, thereby completing the manufacture of acathode plate.

A polyethylene separator having a thickness of 14 μm, a cathode side ofwhich was coated with ceramic, and the organic electrolytic solutionprepared according to Example 1 were used to complete the manufacture ofa lithium battery.

Example G2: CNT 50 μm 1 wt %+SEI-1316 1 wt %

A lithium battery was manufactured in the same manner as in Example G1,except that 96.45 wt % of Li_(1.02)Ni_(0.60)Co_(0.20)Mn_(0.20)O₂ wasused as a cathode active material, and 1 wt % of CNTs having an averagelength of 50 μm were used as a carbonaceous nanostructure.

Example G3: CNT 50 μm 2 wt %+SEI-1316 1 wt %

A lithium battery was manufactured in the same manner as in Example G1,except that 95.45 wt % of Li_(1.02)Ni_(0.60)Co_(0.20)Mn_(0.20)O₂ wasused as a cathode active material, and 2 wt % of CNTs having an averagelength of 50 μm were used as a carbonaceous nanostructure.

Example G4: CNT 50 μm 3 wt %+SEI-1316 1 wt %

A lithium battery was manufactured in the same manner as in Example G1,except that 94.45 wt % of Li_(1.02)Ni_(0.60)Co_(0.20)Mn_(0.20)O₂ wasused as a cathode active material, and 3 wt % of CNTs having an averagelength of 50 μm were used as a carbonaceous nanostructure.

Example G5: CNT 50 μm 1 wt %+SEI-1316 0.5 wt %

A lithium battery was manufactured in the same manner as in Example G1,except that 96.95 wt % of Li_(1.02)Ni_(0.60)Co_(0.20)Mn_(0.20)O₂ wasused as a cathode active material, 0.5 wt % of CNTs having an averagelength of 50 μm were used as a carbonaceous nanostructure, and theorganic electrolytic solution prepared according to Example 3 was usedinstead of the organic electrolytic solution of Example 1.

Example G6: CNT 50 μm 1 wt %+SEI-1316 2 wt %

A lithium battery was manufactured in the same manner as in Example G2,except that 96.95 wt % of Li_(1.02)Ni_(0.60)Co_(0.20)Mn_(0.20)O₂ wasused as a cathode active material, 0.5 wt % of CNTs having an averagelength of 50 μm were used as a carbonaceous nanostructure, and theorganic electrolytic solution prepared according to Example 8 was usedinstead of the organic electrolytic solution of Example 1.

Example G7: CNT 50 μm 1 wt %+SEI-1316 3 wt %

A lithium battery was manufactured in the same manner as in Example G2,except that 96.95 wt % of Li_(1.02)Ni_(0.60)Co_(0.20)Mn_(0.20)O₂ wasused as a cathode active material, 0.5 wt % of CNTs having an averagelength of 50 μm were used as a carbonaceous nanostructure, and theorganic electrolytic solution prepared according to Example 9 was usedinstead of the organic electrolytic solution of Example 1.

Example G8: CNT 5 μm 1 wt %+SEI-1316 1 wt %

A lithium battery was manufactured in the same manner as in Example G1,except that 96.45 wt % of Li_(1.02)Ni_(0.60)Co_(0.20)Mn_(0.20)O₂ wasused as a cathode active material, and 1 wt % of CNTs having an averagelength of 5 μm were used as a carbonaceous nanostructure.

Example G9: CNT 100 μm 1 wt %+SEI-1316 1 wt %

A lithium battery was manufactured in the same manner as in Example G1,except that 96.45 wt % of Li_(1.02)Ni_(0.60)Co_(0.20)Mn_(0.20)O₂ wasused as a cathode active material, and 1 wt % of CNTs having an averagelength of 100 μm were used as a carbonaceous nanostructure.

Reference Example G1: CNT 50 μm 4 wt %+SEI-1316 1 wt %

A lithium battery was manufactured in the same manner as in Example G1,except that 93.45 wt % of Li_(1.02)Ni_(0.60)Co_(0.20)Mn_(0.20)O₂ wasused as a cathode active material, and 4 wt % of CNTs having an averagelength of 50 μm were used as a carbonaceous nanostructure.

Reference Example G2: CNT 200 μm 1 wt %+SEI-1316 1 wt %

A lithium battery was manufactured in the same manner as in Example G1,except that 96.45 wt % of Li_(1.02)Ni_(0.60)Co_(0.20)Mn_(0.20)O₂ wasused as a cathode active material, and 1 wt % of CNTs having an averagelength of 200 μm were used as a carbonaceous nanostructure.

Reference Example G3: CNT 50 μm 1 wt %+SEI-1316 4 wt %

A lithium battery was manufactured in the same manner as in Example G1,except that 96.45 wt % of Li_(0.02)Ni_(0.60)Co_(0.20)Mn_(0.20)O₂ wasused as a cathode active material, 1 wt % of CNTs having an averagelength of 50 μm were used as a carbonaceous nanostructure, and theorganic electrolytic solution prepared according to Example 9a was usedinstead of the organic electrolytic solution of Example 1.

Reference Example G4: CNT 50 μm 0.5 wt %+SEI-1316 1 wt %+NCM111

A lithium battery was manufactured in the same manner as in Example G1,except that LiNi_(1/3)Co_(1/3)Mn_(1/3)O₂ was used as a cathode activematerial instead of Li_(1.02)Ni_(0.60)Co_(0.20)Mn_(0.20)O₂.

Comparative Example G1: CNT 50 μm 1 wt %+SEI-1316 0 wt %

A lithium battery was manufactured in the same manner as in Example G1,except that 96.45 wt % of Li_(1.02)Ni_(0.60)Co_(0.20)Mn_(0.20)O₂ wasused as a cathode active material, 1 wt % of CNTs having an averagelength of 50 μm were used as a carbonaceous nanostructure, and theorganic electrolytic solution prepared according to Comparative Example1 was used instead of the organic electrolytic solution of Example 1.

Comparative Example G2: CNT 50 μm 0 wt %+SEI-1316 1 wt %

A lithium battery was manufactured in the same manner as in Example G1,except that 97.45 wt % of Li_(1.02)Ni_(0.60)Co_(0.20)Mn_(0.20)O₂ wasused as a cathode active material, and the carbonaceous nanostructurewas not added.

Evaluation Example G1: Evaluation of Charge and DischargeCharacteristics at 4.25 V and High Temperature (45° C.)

Charge and discharge characteristics of the lithium batteriesmanufactured according to Examples G1 to G9, Reference Examples G2 toG5, and Comparative Examples G1 and G2 at a high temperature wereevaluated using the same method as that used in Evaluation Example 2,except that the number of charging and discharging cycles was changed to300 cycles.

A part of the charging and discharging experiment results is shown inTable G1 below. A capacity retention ratio at the 300^(th) cycle isdefined using Equation 1 below:

Capacity retention ratio=[discharge capacity at 300^(th) cycle/dischargecapacity at 1^(st) cycle]×100  Equation 1

TABLE 1 Capacity retention ratio at 300^(th) cycle [%] Example G1 (CNT50 μm 0.5 wt % + SEI-1316 1 wt %) 91 Example G2 (CNT 50 μm 1 wt % +SEI-1316 1 wt %) 90 Example G3 (CNT 50 μm 2 wt % + SEI-1316 1 wt %) 88Example G4 (CNT 50 μm 3 wt % + SEI-1316 1 wt %) 87 Example G5 (CNT 50 μm1 wt % + SEI-1316 0.5 wt %) 89 Example G6 (CNT 50 μm 1 wt % + SEI-1316 2wt %) 87 Example G7 (CNT 50 μm 1 wt % + SEI-1316 3 wt %) 86 Example G8(CNT 5 μm 1 wt % + SEI-1316 1 wt %) 90 Example G9 (CNT 100 μm 1 wt % +SEI-1316 1 wt %) 88 Reference Example G1 (CNT 50 μm 4 wt % + SEI-1316 841 wt %) Reference Example G2 (CNT 200 μm 1 wt % + SEI-1316 83 1 wt %)Reference Example G3 (CNT 50 μm 1 wt % + SEI-1316 84 4 wt %) ReferenceExample G4 (CNT 50 μm 0.5 wt % + SEI- 80 1316 1 wt % + NCM111)Comparative Example G1 (CNT 50 μm 1 wt % + SEI- 85 1316 0 wt %)Comparative Example G2 (CNT 50 μm 0 wt % + SEI- 85 1316 1 wt %)

As shown in Table G1, the lithium batteries of Examples G1 to G9including the additive and CNT according to embodiments of the presentdisclosure exhibited enhanced lifespan characteristics at a hightemperature, as compared to the lithium batteries of Comparative ExampleG1 not including the additive or Comparative Example G2 not includingCNTs.

In addition, the lithium batteries of Examples G1 to G9 including CNTshaving a length within a certain range exhibited enhanced lifespancharacteristics at a high temperature, as compared to the lithiumbattery of Reference Example G2 including CNTs having a length outsidethe certain range.

Evaluation Example G2: DC-IR Evaluation after High-Temperature (60° C.)Storage

DC-IRs of the lithium batteries of Examples G1 to G9, Reference ExamplesG1 to G3, and Comparative Examples G1 and G2 after high-temperaturestorage were measured using the same method as that used in EvaluationExample 6.

A part of DC-IR increases calculated from measured initial DC-IRs andthe measured DC-IRs after high-temperature storage is shown in Table G2below. A DC-IR increase is represented by Equation 6 below:

Direct current internal resistance increase [%]=[direct current internalresistance after high-temperature storage/initial direct currentinternal resistance]×100  Equation 6

TABLE G2 DC-IR increase after 30-day storage [%] Example G1 (CNT 50 μm0.5 wt % + SEI-1316 1 wt %) 121 Example G2 (CNT 50 μm 1 wt % + SEI-13161 wt %) 122 Example G3 (CNT 50 μm 2 wt % + SEI-1316 1 wt %) 124 ExampleG4 (CNT 50 μm 3 wt % + SEI-1316 1 wt %) 126 Example G5 (CNT 50 μm 1 wt% + SEI-1316 0.5 wt %) 124 Example G6 (CNT 50 μm 1 wt % + SEI-1316 2 wt%) 125 Example G7 (CNT 50 μm 1 wt % + SEI-1316 3 wt %) 127 Example G8(CNT 5 μm 1 wt % + SEI-1316 1 wt %) 123 Example G9 (CNT 100 μm 1 wt % +SEI-1316 1 wt %) 124 Reference Example G1 (CNT 50 μm 4 wt % + SEI-1316130 1 wt %) Reference Example G2 (CNT 200 μm 1 wt % + SEI-1316 131 1 wt%) Reference Example G3 (CNT 50 μm 1 wt % + SEI-1316 132 4 wt %)Comparative Example G1 (CNT 50 μm 1 wt % + SEI- 130 1316 0 wt %)Comparative Example G2 (CNT 50 μm 0 wt % + SEI- 131 1316 1 wt %)

As shown in Table G2, the lithium batteries of Examples G1 to G9including the additive and CNTs according to embodiments of the presentdisclosure exhibited lower DC-IR increases than those of the lithiumbatteries of Comparative Example G1 not including the additive andComparative Example G2 not including CNTs.

Evaluation Example G3: Impregnation Amount Evaluation

Impregnation amount measurement was performed on the cathodes fabricatedaccording to Examples G1 to G9, Reference Examples G1 to G3, andComparative Examples G1 and G2 using the following method.

An electrolytic solution was prepared by dissolving 1.15 M LiPF₆ in amixed solvent of ethylene carbonate/ethyl methyl carbonate/dimethylcarbonate (EC/EMC/DMC) in a volume ratio of 2:4:4 and adding 1 wt % ofvinylene carbonate (VC) to the resulting solution. Each cathode platewas cut to a size of 3 cm×6 cm, and then immersed in the preparedelectrolytic solution to quantitatively measure the amount of theelectrolytic solution with which the cathode plate was impregnated for300 seconds. The impregnation amounts were measured using an AttensionSigma device after each cathode plate was immersed in the electrolyticsolution for 300 seconds.

The measured impregnation amounts are shown in Table G3 below.

TABLE G3 Impregnation amount [mg, at 300 sec] Example G1 (CNT 50 μm 0.5wt % + SEI-1316 1 wt %) 23.0 Example G2 (CNT 50 μm 1 wt % + SEI-1316 1wt %) 20.5 Example G3 (CNT 50 μm 2 wt % + SEI-1316 1 wt %) 17.3 ExampleG4 (CNT 50 μm 3 wt % + SEI-1316 1 wt %) 14.7 Example G5 (CNT 50 μm 1 wt% + SEI-1316 0.5 wt %) 17.9 Example G6 (CNT 50 μm 1 wt % + SEI-1316 2 wt%) 15.2 Example G7 (CNT 50 μm 1 wt % + SEI-1316 3 wt %) 14.4 Example G8(CNT 5 μm 1 wt % + SEI-1316 1 wt %) 21.8 Example G9 (CNT 100 μm 1 wt % +SEI-1316 1 wt %) 16.9 Reference Example G1 (CNT 50 μm 4 wt % + SEI-131611.6 1 wt %) Reference Example G2 (CNT 200 μm 1 wt % + SEI-1316 10.1 1wt %) Reference Example G3 (CNT 50 μm 1 wt % + SEI-1316 12.0 4 wt %)Comparative Example G1 (CNT 50 μm 1 wt % + SEI- 12.1 1316 0 wt %)Comparative Example G2 (CNT 50 μm 0 wt % + SEI- 11.9 1316 1 wt %)

As shown in Table G2, the lithium batteries of Examples G1 to G4including the additive and CNTs according to embodiments of the presentdisclosure exhibited increased impregnation amounts, as compared to thelithium batteries of Reference Example G1 not including the additive andComparative Example G2 not including CNTs.

In addition, the lithium batteries of Examples G1 to G9 including CNTshaving a length within a certain range exhibited increased impregnationamounts, as compared to the lithium battery of Reference Example G2including CNTs having a length outside the certain range.

Since the lithium batteries of Examples G1 to G9 have enhancedimpregnation characteristics, a contact area between the electrode andthe electrolytic solution is increased. Accordingly, electrode reactionreversibility is enhanced, and thus the lithium batteries have a reducedinternal resistance, resulting in enhancement of cycle characteristicsof the lithium batteries.

By way of summation and review, when lithium batteries operate at highoperating voltages, aqueous electrolytic solutions highly reactive tolithium may not be suitable for use in such lithium batteries. Lithiumbatteries generally use organic electrolytic solutions. An organicelectrolytic solution is prepared by dissolving a lithium salt in anorganic solvent. An organic solvent with stability at high voltages,high ionic conductivity, high dielectric constant, and low viscosity maybe used.

When a lithium battery uses a general organic electrolytic solutionincluding a carbonate-based polar non-aqueous solvent, an irreversiblereaction, in which charges are excessively used due to a side reactionbetween the anode/cathode and the organic electrolytic solution, mayoccur during initial charging. As a result of such an irreversiblereaction, a passivation layer, such as a solid electrolyte interface(SEI) layer, may be formed at a surface of an anode. In addition, aprotection layer is formed at a surface of a cathode.

In this regard, the SEI layer and/or the protection layer, formed usingan existing organic electrolytic solution, may be easily degraded. Forexample, such an SEI layer and/or protection layer may exhibit decreasedstability at a high temperature.

Therefore, an organic electrolytic solution capable of forming an SEIlayer and/or a protection layer having improved high-temperaturestability is desirable.

Embodiments provide a lithium battery including a cathode including acarbonaceous nanostructure and an organic electrolytic solutionincluding a novel bicyclic sulfate-based additive. The lithium batteryaccording to embodiments exhibits enhanced high-temperaturecharacteristics and enhanced lifespan characteristics.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of ordinary skill in the art asof the filing of the present application, features, characteristics,and/or elements described in connection with a particular embodiment maybe used singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope thereof as set forth in thefollowing claims.

What is claimed is:
 1. A lithium battery, comprising: a cathodeincluding a cathode active material; an anode including an anode activematerial; and an organic electrolytic solution between the cathode andthe anode, wherein the cathode includes a carbonaceous nanostructure,and the organic electrolytic solution includes a first lithium salt, anorganic solvent, and a bicyclic sulfate-based compound represented byFormula 1 below:

wherein, in Formula 1, each of A₁, A₂, A₃, and A₄ is independently acovalent bond, a substituted or unsubstituted C₁-C₅ alkylene group, acarbonyl group, or a sulfinyl group, wherein both A₁ and A₂ are not acovalent bond and both A₃ and A₄ are not a covalent bond.
 2. The lithiumbattery as claimed in claim 1, wherein at least one of A₁, A₂, A₃, andA₄ is an unsubstituted or substituted C₁-C₅ alkylene group, wherein asubstituent of the substituted C₁-C₅ alkylene group is at least oneselected from a halogen-substituted or unsubstituted C₁-C₂₀ alkyl group,a halogen-substituted or unsubstituted C₂-C₂₀ alkenyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkynyl group, ahalogen-substituted or unsubstituted C₃-C₂₀ cycloalkenyl group, ahalogen-substituted or unsubstituted C₃-C₂₀ heterocyclic group, ahalogen-substituted or unsubstituted C₆-C₄₀ aryl group, ahalogen-substituted or unsubstituted C₂-C₄₀ heteroaryl group, or a polarfunctional group having at least one heteroatom.
 3. The lithium batteryas claimed in claim 1, wherein at least one of A₁, A₂, A₃, and A₄ is anunsubstituted or substituted C₁-C₅ alkylene group, wherein a substituentof the substituted C₁-C₅ alkylene group is a halogen, a methyl group, anethyl group, a propyl group, an isopropyl group, a butyl group, atert-butyl group, a trifluoromethyl group, a tetrafluoroethyl group, aphenyl group, a naphthyl group, a tetrafluorophenyl group, a pyrrolylgroup, or a pyridinyl group.
 4. The lithium battery as claimed in claim2, wherein the substituted C₁-C₅ alkylene group is substituted with apolar functional group including at least one heteroatom, wherein thepolar functional group is at least one selected from —F, —Cl, —Br, —I,—C(═O)OR¹⁶, —OR¹⁶, —OC(═O)OR¹⁶, —R¹⁵OC(═O)OR¹⁶, —C(═O)R¹⁶, —R¹⁵C(═O)R¹⁶,—OC(═O)R¹⁶, —R¹⁵OC(═O)R¹⁶, —C(═O)—O—C(═O)R¹⁶, —R¹⁵C(═O)—O—C(═O)R¹⁶,—SR¹⁶, —R¹⁵SR¹⁶, —SSR¹⁶, —R¹⁵SSR¹⁶, —S(═O)R¹⁶, —R¹⁵S(═O)R¹⁶,—R¹⁵C(═S)R¹⁶, —R¹⁵C(═S)SR¹⁶, —R¹⁵SO₃R¹⁶, —SO₃R¹⁶, —NNC(═S)R¹⁶,—R¹⁵NNC(═S)R¹⁶, —R¹⁵N═C═S, —NCO, —R¹⁵—NCO, —NO₂, —R¹⁵NO₂, —R¹⁵SO₂R¹⁶,—SO₂R¹⁶,

wherein, in the formulae above, each of R¹¹ and R¹⁵ is independently ahalogen-substituted or unsubstituted C₁-C₂₀ alkylene group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkenylene group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkynylene group, ahalogen-substituted or unsubstituted C₃-C₁₂ cycloalkylene group, ahalogen-substituted or unsubstituted C₆-C₄₀ arylene group, ahalogen-substituted or unsubstituted C₂-C₄₀ heteroarylene group, ahalogen-substituted or unsubstituted C₇-C₁₅ alkylarylene group, or ahalogen-substituted or unsubstituted C₇-C₁₅ aralkylene group; and eachof R¹², R¹³, R¹⁴ and R¹⁶ is independently hydrogen, a halogen, ahalogen-substituted or unsubstituted C₁-C₂₀ alkyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkenyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkynyl group, ahalogen-substituted or unsubstituted C₃-C₁₂ cycloalkyl group, ahalogen-substituted or unsubstituted C₆-C₄₀ aryl group, ahalogen-substituted or unsubstituted C₂-C₄₀ heteroaryl group, ahalogen-substituted or unsubstituted C₇-C₁₅ alkylaryl group, ahalogen-substituted or unsubstituted C₇-C₁₅ trialkylsilyl group, or ahalogen-substituted or unsubstituted C₇-C₁₅ aralkyl group.
 5. Thelithium battery as claimed in claim 1, wherein the bicyclicsulfate-based compound is represented by Formula 2 or 3:

wherein, in Formulae 2 and 3, each of B₁, B₂, B₃, B₄, D₁, and D₂ isindependently —C(E₁)(E₂)-, a carbonyl group, or a sulfinyl group; andeach of E₁ and E₂ is independently hydrogen, a halogen, ahalogen-substituted or unsubstituted C₁-C₂₀ alkyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkenyl group, ahalogen-substituted or unsubstituted C₂-C₂₀ alkynyl group, ahalogen-substituted or unsubstituted C₃-C₂₀ cycloalkenyl group, ahalogen-substituted or unsubstituted C₃-C₂₀ heterocyclic group, ahalogen-substituted or unsubstituted C₆-C₄₀ aryl group, or ahalogen-substituted or unsubstituted C₂-C₄₀ heteroaryl group.
 6. Thelithium battery as claimed in claim 5, wherein each of E₁ and E₂ isindependently hydrogen, a halogen, a halogen-substituted orunsubstituted C₁-C₁₀ alkyl group, a halogen-substituted or unsubstitutedC₆-C₄₀ aryl group, or a halogen-substituted or unsubstituted C₂-C₄₀heteroaryl group.
 7. The lithium battery as claimed in claim 5, whereineach of E₁ and E₂ is independently at least one selected from hydrogen,fluorine (F), chlorine (Cl), bromine (Br), iodine (I), a methyl group,an ethyl group, a propyl group, an isopropyl group, a butyl group, atert-butyl group, a trifluoromethyl group, a tetrafluoroethyl group, aphenyl group, a naphthyl group, a tetrafluorophenyl group, a pyrrolylgroup, and a pyridinyl group.
 8. The lithium battery as claimed in claim1, wherein the bicyclic sulfate-based compound is represented by Formula4 or 5:

wherein, in Formulae 4 and 5, each of R₁, R₂, R₃, R₄, R₂₁, R₂₂, R₂₃,R₂₄, R₂₅, R₂₆, R₂₇, and R₂₈ is independently hydrogen, a halogen, ahalogen-substituted or unsubstituted C₁-C₂₀ alkyl group, ahalogen-substituted or unsubstituted C₆-C₄₀ aryl group, or ahalogen-substituted or unsubstituted C₂-C₄₀ heteroaryl group.
 9. Thelithium battery as claimed in claim 8, wherein each of R₁, R₂, R₃, R₄,R₂₁, R₂₂, R₂₃, R₂₄, R₂₅, R₂₆, R₂₇, and R₂₈ is independently hydrogen, F,Cl, Br, I, a methyl group, an ethyl group, a propyl group, an isopropylgroup, a butyl group, a tert-butyl group, a trifluoromethyl group, atetrafluoroethyl group, a phenyl group, a naphthyl group, atetrafluorophenyl group, a pyrrolyl group, and a pyridinyl group. 10.The lithium battery as claimed in claim 1, wherein the bicyclicsulfate-based compound is represented by one of Formulae 6 to 17 below:


11. The lithium battery as claimed in claim 1, wherein an amount of thebicyclic sulfate-based compound is from about 0.4 wt % to about 5 wt %based on a total weight of the organic electrolytic solution.
 12. Thelithium battery as claimed in claim 1, wherein an amount of the bicyclicsulfate-based compound is from about 0.4 wt % to about 3 wt % based on atotal weight of the organic electrolytic solution.
 13. The lithiumbattery as claimed in claim 1, wherein the first lithium salt in theorganic electrolytic solution includes at least one selected from LiPF₆,LiBF₄, LiSbF₆, LiAsF₆, LiClO₄, LiCF₃SO₃, Li(CF₃SO₂)₂N, LiC₄F₉SO₃,LiAlO₂, LiAlCl₄, LiN(C_(x)F_(2x+1)SO₂)(C_(y)F_(2y+1)SO₂) where 2≤x≤20and 2≤y≤20, LiCl, and LiI.
 14. The lithium battery as claimed in claim1, wherein the organic electrolytic solution further includes a cycliccarbonate compound, wherein the cyclic carbonate compound is selectedfrom vinylene carbonate (VC), VC substituted with at least onesubstituent selected from a halogen, a cyano (CN) group, and a nitrogroup (NO₂), vinylethylene carbonate (VEC), VEC substituted with atleast one substituent selected from a halogen, CN, and NO₂,fluoroethylene carbonate (FEC), and FEC substituted with at least onesubstituent selected from a halogen, CN, and NO₂.
 15. The lithiumbattery as claimed in claim 14, wherein an amount of the cycliccarbonate compound is from about 0.01 wt % to about 5 wt % based on atotal weight of the organic electrolytic solution.
 16. The lithiumbattery as claimed in claim 1, wherein the organic electrolytic solutionfurther includes a second lithium salt represented by one of Formulae 18to 25 below:


17. The lithium battery as claimed in claim 16, wherein an amount of thesecond lithium salt is from about 0.1 wt % to about 5 wt % based on atotal weight of the organic electrolytic solution.
 18. The lithiumbattery as claimed in claim 1, wherein the carbonaceous nanostructureincludes at least one selected from a one-dimensional carbonaceousnanostructure and a two-dimensional carbonaceous nanostructure.
 19. Thelithium battery as claimed in claim 1, wherein the carbonaceousnanostructure includes at least one selected from carbon nanotubes(CNTs), carbon nanofibers, graphene, graphene nanosheets, hollow carbon,porous carbon, and mesoporous carbon.
 20. The lithium battery as claimedin claim 1, wherein the carbonaceous nanostructure has an average lengthof about 1 μm to about 200 μm.
 21. The lithium battery as claimed inclaim 1, wherein an amount of the carbonaceous nanostructure is fromabout 0.5 wt % to about 5 wt % based on a total weight of a cathodemixture.
 22. The lithium battery as claimed in claim 1, wherein anamount of the carbonaceous nanostructure is from about 0.5 wt % to about3 wt % based on a total weight of a cathode mixture.
 23. The lithiumbattery as claimed in claim 1, wherein the cathode includes anickel-containing layered lithium transition metal oxide.
 24. Thelithium battery as claimed in claim 23, wherein a content of nickel inthe lithium transition metal oxide is about 60 mol % or more withrespect to a total number of moles of transition metals.
 25. The lithiumbattery as claimed in claim 23, wherein the lithium transition metaloxide is a compound represented by Formula 27 or 28 below:LiNi_(x)Co_(y)Mn_(z)O₂  <Formula 27>LiNi_(x)Co_(y)Al_(z)O₂  <Formula 28> wherein, in Formulae 27 and 28,0.6≤x≤0.95, 0<y≤0.2, 0<z≤0.2, and x+y+z=1